Requienia ammonia SOLD
System: Cretaceous.
Floor: Barremian.
Origin: Orgon, department of Bouches-du-Rhône, France.
Measurements: 10.2 cm x 9.5 cm
Requienia was a rudist, that is, a bivalve but formed by two different valves as a result of its fixation in shallow waters. The valve fixed to the substrate takes on an elongated conical shape and increases in thickness, thus resisting the waves and distancing the opening of the shell from the bottom. The free valve is usually smaller and functions as an operculum.
